u. $. Department of the Interior BLM·Alaska Open File Report 59 

Bureau of Land Management BLM/AKST-96..o13+6700+020 

December 1996 

Alaska S1alEl Office 

222 West 7th, #13 

Anchorage, Alaska 99513 

Waterfowl Production and Initial Effects of Fire 

on Wetlands In the Pah River Flats: Final Report 

INVESTIGATORS: R.R. Jandt and M.L. Fisk 
Waterfowl Production and Initial Effects of Fire on
 

Wetlands in the Pah River Flats: Final Report
 

INVESTIGATORS: R.R. Jandt and M.L. Fisk 

Open File Report 59 

December 1996 
Table of Contents
 

Introduction 1 

Study Area 3 

Methods 3 

Results 3 

Discussion 8 

Waterfowl Production in the Pah River Flats 8 

Burned Areas/Ecosystem Effects 9 

Burned Areas/Production 10 

Conclusions 11 

Literature Cited 13 

Tables 

Table 1. Average brood size for most commonly observed species 5 

Table 2. Analysis of variance (ANOYA) table for n=59 ponds 6 

Table 3. Families and number of aquatic invertebrate organisms collected 7 

Table 4. Estimated duck production annually in the Pah River Flats 8 

Figures 

Figure 1. Pah River Flats plot locations and fire perimeters 2 

Figure 2. Species composition by percentage of observed duck broods in the Pah River Flats 4 

Figure 3. Species composition by percentage of adult ducks in the Pah River Flats 5 

Figure 4A. Number of duck broods by plot for each of three years after the 1992 fire 6 

Figure 4B. Number of duck broods by plot in 1989 (preburn) in the Pah River Flats survey area 6 

Figure 5. Graph comparing mean duck brood production on ponds 6 

Figure 6. Average duck brood production over three years 8 

Figure 7. Comparison of diving duck broods 9 

Appendix 

Appendix A 12 
Waterfowl Production and Initial Effects of Fire on 

Wetlands in the Pah River Flats: Final Report 

Abstract 

Waterfowl brood surveys were conducted in the Pah River Flats, Alaska during July of 

1995. Duck production was not significantly different between plots burned in a 1992 

wildfire and unburned plots for the third year following the burn. Fire did not produce 

any statistically detectable positive or negative effects on waterfowl production or habitat in the first three years following the fire. Fewer diver broods were found in burned 

ponds during all three years following the fire. Dabbler broods were more numerous 

on moderately burned ponds and less numerous on severely burned ponds, especially 

in the first two years. The four-year average for waterfowl produced from this wetlands complex was 1,147±180 young ducks annually, or 16.4 young ducks/km2• American wigeon (Anas americana), greater scaup (Aythya marila) and green-winged teal (Anas 

crecca) were the predominant species. 

INTRODUCTION 

Ground brood counts based on the number and nity to study the effects of fire on waterfowl and 

size of broods counted during the peak of breed­ the taiga wetlands ecosystem, with the advantage 

ing season in July have been used in several places of having pre-fire production data. 

in Alaska to estimate waterfowl production Surveys to record post-fire waterfowl produc­

(Brubaker and Witmer 1989, Doyle 1989, USFWS tion began in 1993 and continued through 1995 

1991). Information on waterfowl habitat quantity, (Jandt and Morkill1994, this report). The goal of 

quality, relative productivity and utilization is this study was to obtain information on wateressential to establish informed management fowl production, habitats and effects of fire on 

policy relating to wetlands on public land. wetlands ecosystems. This information will be 

The Bureau of Land Management (BLM) con­ useful when managers make land use decisions 

ducted brood surveys in the Pah River Flats in and choose fire management options. 

1989, when production was estimated at 610±138 We would like to express our gratitude to the 

young ducks (Anderson and Robinson 1991). This USFWS, Koyukuk/Nowitna Refuge stafffor helpfigure was thought to be lower than usual in this ing with fuel logistics and the loan of a cabin. H. 

region due to extensive spring flooding. From Brownell, M. Fisk, R. Jandt, A. Koscis and A. 

1990 to 1992, the U.s. Fish and Wildlife Service Morkill participated in the collection ofthe data. 

(USFWS) included the Pah River Flats in the larger C.R. Meyers provided botanical expertise and A. 

refuge survey for the Koyukuk-Nowitna National Batten, at the University ofAlaska Fairbanks HerWildlife Refuge. As a result, sampling intensity barium, helped document the range extensions. 

declined, and little specific pond production in­ Invertebrate identifications were provided by M. 

formation is available for the Pah River Flats dur­ Vinson and staff at the BLM Aquatic Ecosystem 

ing that period. Lab, Utah State University. We thank pilot A. 

In July 1992 a lightning-caused wildfire burned Greenblatt of Wright's Air for sharing our camp 

over 2000 ha of the Pah River Flats (Fig. 1). Two of and providing safe and efficient transportation. 

the 10 plots surveyed in 1989 were entirely within Thanks also to the folks at Alaska Fire Servicethe fire perimeter, and parts of several others were Galena Zone and pilot J. Patrick of Trans Alaska 

affected. The fire provided a window of opportu- Helicopters for logistics and helicopter support. 

1 
N 
STUDY AREA 

The Pah River Flats, located just below the Arctic Circle in northcentral Alaska, is a basin between 

the Kobuk and Koyukuk rivers that covers about 

728 km2 (Fig. 1). 

The climate in this region is cold and continental with temperature extremes ranging from 900 F 

to -680 F and an average yearly precipitation of 32 

cm (data from Hughes). 

The Pah River flows from the northeast comer 

of the study area to the south, continuing to the 

northwest comer in a wide arc. North ofthe study 

area, the river makes its way through the 

Lockwood Hills and eventually empties into the 

Kobuk River. 

Upland vegetation is a typical taiga mosaic of 

sedge meadow, spruce forest, deciduous shrub 

and treeless tundra. More than 500 ponds and 

lakes, in addition to the stream and river riparian 

habitat, form a wetland complex that is underlain 

by continuous permafrost. Many ofthe ponds are 

cryogenic (cave-in) ponds formed by local thawing of perennially frozen ground. Other types of 

ponds include oxbows, river-flooded lowlands, 

and bog lakes. The development of littoral zones 

varies greatly between ponds, but most support 

a border of emergent vegetation cover with an average 22% floating aquatic plants. Common 

aquatic plants include bur reed (Sparganium sp.), 

pondweeds (Potamogeton spp.), bladderwort(Utricularia spp.), and pond lily (Nuphar polysepalum). 

Plant nomenclature follows Hulten (1968). 

METHODS 

The Pah River Flats basin contains approximately 289 km2 of lowland/wetlands complex 

containing numerous small ponds and lakes up 

to 80 ha in size. The survey area was divided into 

2.6-km2 plots defined by section lines on U.S. Geological Survey (USGS) 1:63,360-scale topographic 

maps. Each plotwas originally stratified as "key," 

"moderate" or "poor" habitat based onwater surface area, number of ponds and the presence of 

streams that appeared on the maps. 

A stratified random sampling scheme was used 

to select sample plots in 1989 (Anderson and 

Robinson 1991a). The same ponds were sampled 

in 1993, 1994 and 1995, except the least productive of the three strata was dropped. This "low 

production" stratum represented about 21,000 ha, 

butrequired access by helicopter. In addition, two 

sample plots surveyed in 1989 had no observed 

broods. Therefore, we decided to concentrate observations on the most productive wetlands. 

During post-fire surveys from 1993 through 

1995, eight plots were sampled: five in the "key" 

and three in the "moderate" stratum (Fig. 1). The 

"key" and "moderate" strata totaled 7,000 ha and 

provided the estimates for total production. Disregarding the potential broods on the remaining 

21,000 ha of "poor" habitat means that production estimates should be regarded as minimums. 

A Cessna 185 floatplane or Bell206L helicopter 

provided access to individual plots. Sampling for 

1995 was conducted July 20-24. Observers walked 

or canoed around the margins of all ponds in 

sample plots using binoculars and spotting scopes 

to identify waterfowl. Spring water levels were 

moderate due to an early breakup in 1995. The 

water level inmost ponds was average to low during the July survey. 

RESULTS 

A total of 113 broods and 442 young ducks were 

observed in 1995. The expanded estimate of duck 

broods in the Pah River Flats was 266 ±85 broods, 

a coefficient of variation (CV) of 0.32. When corrected for sampling fraction after Cochran (1977:p. 

92), the CV is reduced by half, bringing it within 

the target range of about 150/0. 

The most variation occurred in the three "moderate" plots, which ranged from one to 12 broods 

and accounted for 79% of the variance in the production estimate. 

The 1995 production of young ducks was 1,258 

±445. The species composition ofbroods was similar to previous years. American wigeons were 

most numerous, accounting for 33% of the total 

broods observed (Fig. 2). Green-winged teals and 

greater scaup each represented 170/0 of the total 

broods observed (Fig. 2). 

The average brood size in 1995 across age 

3 
Greenwinged Teal 

11% 

Figure 2. Species composition by percentage of observed duck broods in the Pah River Flats, Alaska, July 1995. 

Other Manard ,,) 

Seoler 11% 8%

3% 

SCaup American 1n'0 Wigeon 

33% 

Northern
 

Pintail
 

11%
 

classes (considering only observed broods of 

known size) for the most frequently observed 

dabblers was 4.1 young for wigeon (n=38), 6.0 

for green-winged teal (n=19), and 4.4 for northern pintail (Anas acuta) (n=12) (Table 1). The average brood size for greater scaup, the only diver 

observed with broods, was 4.9 (n=30). This brood 

size for scaup was down somewhat from its previous estimate of 6.5 (n=17) in 1994, and less than 

the historical average for Alaska of 6.22, compiled 

by the USFWS from 1984 to 1989 (Hodges and 

Witmer 1990). The decrease was not explained by 

brood age as scaup broods from both years were 

young: 70% Class I.broods in 1994 and 80% in 

1995. Otherwise, the four-year average brood size 

for the major species represented is comparable 

to Alaska averages (Table 1). 

Observers recorded a total of 459 adult ducks 

in 1995. Scaup was the most common diver and 

adult duck, accounting for 33% oftotal adults (Fig. 

3). All positively identified scaup were greater 

scaup, but due to their similarity, some lesser 

scaup (Aythya affinis) could have been in the flocks 

as well. Surf seaters (Melanitta perspicillata), black 

seaters (M. nigra), and bufflehead (B. albeola) were 

the other divers observed. Wigeon was the most 

common dabbler duck, accounting for 30% of the 

total adults (Fig. 3). Green-winged teal, mallard 

(Anas platyrhynchos), northern pintail, and northern shoveler (A. clypeata), made up the balance of 

dabbling ducks. Atotal of 19 geese were observed, 

induding the greater white-fronted goose (Anser . 

albifrons) and Canada goose (Branta canadensis). 

Also reported were three sandhill cranes (Crus 

canadensis), 36 red-necked grebes (Podiceps 

grisegena) and a pair of Pacific loons (Cavia pacifica). 

Comparing production on sample plots affected 

bythe burn to unburned plots did not demonstrate 

any significant effects on waterfowl broods, possibly due to the large variability among plots and 

among different years (Figs. 4A and 4B). Of the 

eight plots studied, four had little or no burn, two 

were at least half-burned and two were completely 

within the burn perimeter (Fig. 4A). 

The two plots with the highest duck production 

in 1995 (and 1994) were an unburned plot, K-5 

(n=40 broods), and a burned plot, K-4 (n=26). It 

was difficult to classify plot areas with a mixture 

ofburn effects as burned or unburned, so data was 

analyzed by pond as well. 

Four classes of fire severity were determined 

for 57 ponds: unburned, partially burned, burned 

and severely burned. Partiallyburned ponds were 

4 
Other Mallard

11 % 60/0 Seoter 

50/0 

American 

Wigeon 

30% 

Scaup 

330/0 Green.. 

winged Teal 

11% 

Pintail
 

4%
 

Figure 3. Species composition by percentage of adult ducks in the PahRiver Flats, Alaska, July 1995. 

Burned ponds (n=32) (including severely 

burned) had slightly lower production, measured 

excluded from analysis in these results except 

where specifically mentioned. Burned ponds had 

most of in duck broods, in 1993. By 1994, production of the upland perimeter burned, but often a 

band of burned ponds was equal to unburned ponds riparian vegetation remained between the 

burn and the water's edge. Severely burned ponds (n=22), and by 1995 the production of burned

were burned down to the pond margin over a sub­ ponds had surpassed production of unburned 

stantial portion of the perimeter. ponds (Fig. 5). However, the variances associated 

Brood Size 

Species 1989 1993 1994 1995 4-Year 

Average 

n= State 

Average 

American wigeon 3.8 5.5 5.2 4.1 4.7 109 4.9 

Greater scaup 5.4 7.1 6.5 4.9 6.0 57 6.2 

Green-winged teal 4.6 4.6 3.5 6.0 4.7 56 4.7 

Mallard 1.3 2.8 4.0 3.8 3.0 29 4.5 

Northern pintail 4.3 4.4 5.0 4.4 4.5 34 4.3 

Table 1. Average brood size for most commonly observed species by year and compared to the USFWS Alaska historic 

average from 1984-1989 (Hodges and Witmer 1990). 

5 
Source d.f. 55 MS F p 

Burn treatment 3 11.16 3.72 0.22 0.883 

Year 2 31.22 15.61 5.00 0.008* 

Interaction 6 32.60 5.43 1.74 0.119 

Error (residual) 104 324.48 3.12 

Total 115 3206.20 27.88 

Table 2. Analysis of variance (ANOVA) table for n=59 ponds over 3 years (1993-1995) in each of 4 burn categories (unburned, partially burned, burned, severely burned). Significance indicated by *. 

80 

70 

60 

50 

40 

30 

20 

10 

K­ M K· K­ M K· K· M 

5 ·3 2 3 -1 4 1 -2 

illlburned . 'partially burnel burned 

Figure 4A. Number of duck broods by plot for each of three 

years after the 1992 fire. 

198& 

,.
 

,.
 

• 12 

g 

05'0 

g 

0 • 

K·S '1-3 K·2 

II
 K·3 '1·1 K·. K·, '1-2 

Figure 5. Graph comparing mean duck brood production on 

ponds with (n=32) or without (n=22) burn effect over the three 

years following a wildfire. 

with mean production estimates are high enough 

that these differences are not statistically significant, as illustrated for the three burn classes in 

(Fig. 6.) 

There were statistically fewer diver broods on 

burned ponds in a t-test on three years of pooled 

post-fire data (p < 0.05) (Fig 7.) Dabbler broods, 

in contrast, tended to be more numerous on 

burned ponds (p =: 0.07), but less numerous on 

the severely burned ponds (not significant). 

When three years of post-burn production data 

on ponds were compared in an ANOVA (type I, 

repeated measures), only the year effect was significant (F;;::3.43, p<0.05), and the burn effect was 

not (Table 2). 

Specimens of important aquatic and emergent 

plants were collected opportunistically in 1993 Figure 48. Number of duck broods by plot in1989 (preburn)
 

in the Pah River Flats survey area. and 1994, since little or no previous botanical col6 
lecting had been done in this remote area. A list 

of plants collected during the surveys is located 

in Appendix A. These collections extend or expand the known ranges of four species that are 

found mostly in pond or stream riparian areas. 

Calla palustris is commonly known as wild calla. 

Plants are 20-45 cm tall and leaf blades are 6-15 

cmlong and 4-12 emwide, with red berries (Welsh 

1974). Nymphaea tetragona is commonly known as 

the dwarf water lily. The leaves float and are 

shaped much like an arrowhead, but are 2.5-8 cm 

wide with a leathery look (Welsh 1974). 

Potamogeton epihydrus var. ramosus, also known as 

nuttall pondweed, has submersed leaves 20 cm 

long and 3-10 mm wide and floating leaves that 

are more oblong than the submersed leaves (Welsh 

1974). Lysimachia thyrsiflora or tufted loosestrife 

is 0.2-0.8 m tall with leaves that are scale-like and 

Order Common Name 

tubifex worm 

Unburned 

(#) 

Burned 

(#) 

Annelids: Tubificida 6 3 

Arthropods: Hydracarina water mite 0 3 

(crustaceans) Amphipoda scud 7 9 

Cladocera water flea 1 53 

Copepoda copepod 35 17 

Ostracoda seed shrimp 0 1 

(insects) Coleoptera water beetle 17 10 

Diptera midge & cranefly 4 11 

larvae 

Odonata dragon, damsel, & 7 16 

caddisfly larvae 

Hemiptera water boatmen & 6 12 

water striders 

Gastropods& Limnophila snails 9 11 

pelecypods: 

Veneroidea mussels 3 4 

Flatworms: Tricladida planarians 3 1 

Other: Nematophora horsehair worms 0 5 

Table 3. Families and number of aquatic invertebrate organisms collected from lakes with burned VB. unburned margins in 

the Pah River Flats, 1994. Most were not identified beyond the level of order. 

7 
enlarged at the top of the plant and smaller at the 

base, (Welsh1974). Drosera anglica, the long-leaved 

sundew, is a carnivorous plant that generally 

grows south of the Yukon River. Hulten (1968) 

noted a disjunct population in the locality of our 

study area. 

Aquatic invertebrates were collected from three 

ponds (one unburned pond and two ponds with 

12 ~---,.-----'--:------'-.2.,"""--""""1-:::::::-'4 

1 t:::::::::::::::::r:·::::::::::·:::::::::::::::::::::::t::::::::.:::::::':: ::t::::··:·, 

6 

4 

2 

o 

12 ,....----,...----.:......-...-­ ""'"'---....-...-'=-'1.• 

10 ,> : ·· ·..1 

8 ·i· · "'"T"" 

6 ~-----+---

4 L.--....=~

2 

o 

12 .-----,---.:......-...--...--...--~=....,

10 ~·..··~·-i· ..·_·..·~_·..~--+--_···_ ..~---l··

8 

6 

4 

2 

o 

Figure 6. Average duck brood production over three years, 

showing mean and standard deviation, for ponds with three 

levels of burn effect. 

burned margins) in 1994. A total of 248 organisms 

from 32 taxa were identified and classified from 

the samples (Table 3). In general, the biotic indices seemed to indicate a water quality rating of 

excellent in tests designed to detect organic pollution. More species were islolated from the burn 

sample (n=25) than from the unburned (n=18), but 

species richness, based on EPT richness (the number of different taxa in three pollution-sensitive 

insect orders) and dominant family contribution, 

was slightly higher in the unburned sample. 

Voltinism, a measure of life-eycle length, differed 

between the two samples, with long-lived species 

more prevalent in the sample from the unburned 

lake (17.2% vs. 7.5%). Due to the limited sampling 

effort, no attempt was made to attach statistical 

significance to any of the observed differences. 

DISCUSSION 

Waterfowl Production in the Pah Flats 

Interestingly, expanded brood production in 

1995 and 1994 was almost identical: 266 and 260, 

respectively. The mean production of young ducks 

in 1995 (17.9/km2

) was slightly lower than the 

20.3/km2 recorded in 1994, but the difference was 

not significant. The estimate of total duck broods 

produced increased each survey year from 1989 

to 1995 (Table 4). Dabbler broods, geese broods 

and total broods were more pumerous in 1995 

Dabblers Divers Total Broods Total Young 

Year: Broods S.D. 

118 ±41 

178 ±81 

Broods S.D. 

22 ±16 

31 ±16 

Broods S.D. 

142 ±47 

231 ±103 

Young S.D. 

616 ±185 

1295 ±575 

1989 

1993 

1994 192 ±60 

176 ±49 

45 ±27 

61 ±35 

260 ±84 

266 ±85 

1419 ±483 

1995 1258 ±445

Table 4. Estimated duck production annually In the Pah River Flats, mcludlng dabbler broods, diver broods, total broods, and 

total young over four survey years. 

8 
Figure 7. Comparison of diving duck broods (mainly s~aup)

on ponds with (n=32) or without (n=22) burn effect In the 

first three years following a wildfire. 

than in 1994, while diver broods remained about 

the same. Species composition changed little from 

1994 to 1995: northern pintail and scoters, including surf scoters and black scoters, both decreased 

by 60/0. 

No plotwas uniformly highest in duck production over all four years, but plot K-5, an unburned 

plot, was consistently a good producer and had 

the highest average production of 110 ±59 young 

ducks, while K-4, a burned plot, was second. The 

continuous high production in plot K-5 could be 

a result of high levels of nutrient exchange with 

the nearby Pah River through a combination of 

seasonal flooding and numerous small channels 

that connect the water bodies within the plot. 

The four-year average production for the whole 

survey area is 1,147 ±264 young ducks annually 

or 16.4 young ducks/km2

, compared to 11.0/km2 

in 1990 (Hodges and Conant 1990) for the 

Koyukuk/Nowitna National Wildlife Refuge just 

south of the Pah River Flats. However, the figure 

for the Koyukuk/Nowitna Wildlife Refuge is 

based on a management area that is much larger 

than the Pah River flats and a substantial portion 

is less suitable waterfowl habitat than the core area 

used for the Pah survey. 

The average brood sizes for the Pah River Flats 

were close to the historical brood sizes for Alaska 

from 1984 to 1989 (Table 1). These results indicate 

that the quality of waterfowl breeding habitat on 

the Pah River Flats is similar to that on designated 

refuges in other areas of Interior Alaska. 

Burned Areas! Ecosystem Effects 

Vegetation recovered in the bum along familiar 

patterns for Interior Alaska taiga. Very little regrowth was observed in heavily charred areas the 

following season, but by two years severely 

burned areas were dotted with vigorous young 

individual plants ofLabrador tea (Ledum ~alustre),

tussock cottongrass (Eriophorum vagtnatum), 

salmonberry (Rubus chamaemorus), and blueberry 

(Vaccinium uliginosum). Revegetation in the moderately burned areas was more rapid, with heavy 

growth of wild rhubarb (Poly~onum alas~~um),

Laborador tea, fireweed (Epilobtum angustifoltum), 

resin birch (Betula glandulosa), and sprouting paper birch (B. papyrifera). 

By the third year, horsetail (Equisetum arvense), 

beauverd spirea (Spiraea beauverdiana), bearberry 

(Arctostaphylos uva-ursi), dwarf birch (Betula nana), 

and willows, especially diamond leafwillow (Salix 

planifolia ssp pulchra), were notable in burned 

spruce stands. Paper birch seedlings were about 

0.5 m and numerous in these stands. Other burned 

areas near pond margins were revegetating as tall 

grass (Calamagrostis canadensis) stands up to 1 m 

in 1994 and approximately 1.5 min 1995. 

Dominantspecies for floating aquatic and emergent vegetation for 1993 and 1994 consisted of 

sedges such as Carex aquatilis, wild calla, buckbean (Menyanthes trifoliata), marsh five finger (Potentilla palustris), marestail (Hippuris vulgaris), and 

grasses. In 1993, severely burned ponds had significantly less (p < 0.05) floating aquatic plant 

cover than burned ponds and burned ponds had 

slightly more than undisturbed ponds. By the second year of the survey, however, both classes of 

burned ponds had slightly more floating cover 

than unburned ponds, and none of the means 

were statistically different (Jandt and Morkill 

1994). If pond nutrients were enhanced by runoff from burned areas, one would expect the effect to be transient, lasting only a year or so fol9 
lowing the bum, as was demonstrated for forest 

floor nutrients following the Rasey Creek fire near 

Fairbanks (MacCracken and Viereck 1990). 

Emergent cover appears to have regrown well 

on burned ponds; within two years it was similar 

in abundance to that on undisturbed ponds. In 

1993, emergent cover averaged 64% on unburned 

lakes and 39% on all types of burned lakes (Jandt 

and Morkill1994), while in 1994 they were close 

to the same, at 220/0 and 15% respectively (R. Jandt, 

unpublished data). Emergent cover typing was of 

a very general nature, but differences in species 

composition did not appear to be great. Sedges 

dominated both burned and unburned emergent 

cover, but lush growths of Calamagrostis and 

fireweed were observed on the banks of some 

burned ponds. It seemed that diversity of the 

emergent vegetation was a favorable factor, as the 

average number of broods was higher on ponds 

having grass or plants other than sedges as the 

dominant emergent growth (Jandt and Morkill 

1994). In 1993-1994, ducks did notshow any other 

pattern of preference for particular floating or 

emergent vegetation types that was statistically 

significant. Dabbler brood density increased 

slightly with an increasing percentage of floating 

and aquatic vegetation cover (Jandt and Morkill 

1994). This finding might be expected for shallow 

ponds, since aquatic vegetation can be used as an 

index of aquatic invertebrate numbers that have 

been shown to correlate with duck densities 

(Joyner 1980). _The qualitative invertebrate 

samples obtained in 1994 provided our first direct look at the trophic level that may underlie 

duck production. 

Although more aquatic invertebrate organisms, 

and more species, were contained in a sample 

from two burned ponds than in a sample from an 

unburned pond, the burned pond's biotic community was dominated by a few families and by 

organisms with short life cycles. Voltinism differed 

between the two samples, with long-lived species 

more prevalent in the sample from the unburned 

lake. One short-lived species-Daphnia, the common water flea-was the most numerous organism in the burned sample, but did not even occur 

in the unburned sample. Taxa requiring more than 

one year to complete their life cycle (semivoltine) 

are more dependent on stable conditions, so their 

absence may indicate instability or a recent disturbance. 

Other concurrent invertebrate sampling byBLM 

fisheries biologists in Interior Alaska seems to indicate that total taxa richness, EPT richness, and 

dominant family percent contribution are indices 

that can be correlated with a decline in water quality in mined areas (C. Kretsinger, pers. comm.). 

Our qualitative results indicate that it may be possible to detect differences in the invertebrate fauna 

of ponds after they are subject to disturbance by 

fire, and the subject warrants further investigation. Earlier studies, such as one on stream invertebrates following the Chicken fire of 1966, found 

little change in the invertebrate fauna (Lotspeich 

et al. 1970). 

Songbird activity recorded in burned areas for 

1994 and 1995 included common redpoll (Carduelis 

flammea), white-crowned sparrow (Zonotrichia 

leucophrys), boreal chickadee (Parus hudsonicus), 

black-backed woodpecker (Picoidesarcticus), rubycrowned kinglet(Regulus satrapa), alderflycatcher 

(Empidonax alnorum), rusty blackbird (Euphagus 

carolinus), savannah sparrow (Passerculus 

sandwichensis), and fox sparrow (Passerella iliaca). 

Otherspecies noted within the whole study area 

were American tree sparrow (Spizella arb0rea), yellow warbler (Dendroica petechia), orange-crowned 

warbler (Vermivora celata), American pipit (Anthus 

rubescens), gray-cheeked thrush (Catharus 

minimus), American robin (Turdus migratorius), 

northern shrike, (Lanius excubitor) pine grosbeak 

(Pinicola enudeator), white-winged crossbill (Loxia 

leucoptera), belted kingfisher (Ceryle alcyon), semipalmated plover (Charadrius semipalmatus); and 

olive-sided flycatcher (Contopus borealis), a candidate for the endangered species list. 

Burned Areas/Production 

No significant direct effects on waterfowl brood 

production were demonstrated on sample plots 

affected by the bumcompared to unburned plots. 

This may be due to the large inherent variability 

among plots and years and the small number (8) 

of plots. Also, the plots did not burn uniformly or 

completely, but generally contained a mixture of 

10 
bum types. Itwould also be difficult to differentiate the effects of other environmental variables, 

such as spring flooding, which affect certain plots 

more than others. Another difficulty was that the 

pre-fire data from 1989 seemed to represent an unusually low production year, so it was of limited 

use in comparison with post-fire data. 

When data was analyzed by ponds to avoid the 

mix of burn effect on plots, another assumption 

was violated: namely, that ponds that are close to 

each other (on the same plot) may not be strictly 

independent samples. Still, using this approach, 

it appears that burned ponds (n=32) had slightly 

lower production in 19.93, but were equal to unburned ponds (n=22) in production by 1994, and 

surpassed them in 1995 (Fig. 5). 

Although these overall differences were not statistically significant, they nevertheless agree with 

anecdotal observations that production seemed 

displaced from severely burned areas for a year 

or two toward the edge of the bum. Some aspects 

of this trend were statistically detectable, such as 

fewer diver broods on the burned ponds (Fig. 7). 

The increase in dabbler broods on moderately 

burned ponds approached significance (p=O.07). 

If this somewhat subtle effect was really due to 

the fire and was not an artifact of some pre-existing difference in the ponds in burned vs. unburned 

areas, it appeared to be transient, with very little 

difference between the groups by the third year 

following the fire (Fig 6). We were able to document that no major positive or negative impacts 

on waterfowl production were associated with the 

first few post-fire breeding seasons. This information will be useful background for fire management planning in this area and other waterfowl 

production areas in taiga ecosystems. 

CONCLUSIONS 

This study illustrates the difficulty of determining the effects of ecosystem change on organisms 

at higher trophic levels. There are many possible 

effects on water nutrients, plant food, cover, 

aquatic invertebrates as food, predators, etc. Effects may differ on different life stages, such as 

nesting and brood-rearing. Also, it is very difficult to isolate natural systems from other factors, 

such as spring flooding, temperature changes, and 

natural abundance and distribution cycles of competitors or predators. 

None of these factors were controlled in this 

study, and the extent of their influence is unknown. It does seem safe to conclude that wildfire did not produce any major detrimental effects 

on waterfowl production or habitat in the three 

seasons following the fire. 

11 
APPENDIX A" Marsh plants collected in the Pah River Flats , 1993-1995 

Plant Common Name Range ext Notes 

Calla palustris wild calla + slight extension 

Caltha natans floating marsh marigold range connection 

Carex aquatilis water sedge 

Carex canescens silvery sedge 

Carex limosa shore sedge 

Chnmaedaphne calyculata cassandra 

Cicuta mackenzieana mackenzie water hemlock 

Drosera anglica long-leaved sundew disjunct population 

Epilobium palustre swamp willow-herb 

Equisetum fluviatile swamp horsetail 

Hippuris vulgaris common marestail 

Lemna trisulca ivy-leaved duckweed 

Lysimachia thyrsiflora tufted loosetrife + 

Nymphaea tetragona dwarf water lily + 

Potamogeton epihydris 

var. ramosus 

nuttall pondweed + 

Potamogeton filiformus filiform pondweed 

Potamogeton perfoliatus clasping long-leaf pondweed 

Rorippa islandica marsh yellowcress 

Sium suave water parsnip 

Sparganium angustifolium narrow-leaved bur reed 

Sparganium sp. sterile specimen* 

Utricularia intermedia flat leaf bladderwort .. *probably S. hyperboreum or S. mzmmum 

12 
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13